The present invention relates to a water deliver system and, more particularly, to an electronic proportioning valve configured to mix hot water and cold water to form a mixed water having a desired temperature and flow rate.
Systems for mixing hot water and cold water in a manner providing for a mixed water of a desired temperature are well known in the art. For example, it is known to provide an electronically controlled proportioning valve for mixing hot water and cold water to provide a mixed water of a desired temperature. Typically, such a system includes a controller operating in a feedback manner such that a temperature measured by a sensor in the outlet of the system is compared to a desired mixed water temperature. The opening and closing of the hot water valve and the cold water valve are controlled based upon the difference between the measured temperature and the desired temperature of the mixed water.
Such known proportioning valves typically exhibit a slow response time. More particularly, there may be a significant delay between the sensor measuring the mixed water temperature and the mixed water temperature being changed in response thereto. As such, large temperature spikes in the mixed water may form as a result of variations of input hot and cold water temperature and pressure. Additionally, traditional proportioning valves operating in a feedback manner typically cause oscillation of the hot and cold water valve positions as the system “hunts” for the desired temperature.
According to an illustrative embodiment of the present invention, a water delivery system is provided for connection to a cold water source, a hot water source, and a mixed water outlet. The water delivery system is configured to provide a mixed water of a desired water temperature to the mixed water outlet. The water delivery system includes a cold water valve adapted to be coupled to the cold water source for receiving cold water and having a cold water outlet. A hot water valve is adapted to be coupled to the hot water source for receiving hot water and has a hot water outlet. A mixing chamber or fluid mixer is configured to receive cold water from the cold water outlet, to receive hot water from the hot water outlet, and to provide a mixed water to the mixed water outlet. A controller is operably coupled to the cold water valve and the hot water valve. The controller is configured to adjust the cold water valve and the hot water valve to regulate a mixed water temperature of the mixed water to substantially correspond to the desired water temperature. The controller is further configured to regulate the mixed water temperature based on at least one characteristic of the cold water, at least one characteristic of the hot water, and at least one characteristic of the mixed water. The controller operates alternatively in a feed forward manner and a feedback manner. The feed forward manner provides for the adjustment of the cold water valve and the hot water valve based on the at least one characteristic of the hot water and the at least one characteristic of the cold water. The feedback manner provides for the adjustment of the cold water valve and the hot water valve based on the at least one characteristic of the mixed water. The controller operates in the feed forward manner when at least one of the cold water source and the hot water source is unstable.
According to a further illustrative embodiment of the present invention, a method is provided for controlling a water delivery system to provide a mixed water to a mixed water outlet. The water delivery system includes a cold water valve connected to a cold water source, a hot water source connected to a hot water source, and a mixer for combining cold water from the cold water valve and hot water from the hot water valve, the mixer being connected to the mixed water outlet. The method includes the steps of receiving an input representing a desired temperature of the mixed water being provided to the mixed water outlet, and monitoring at least one characteristic of the cold water provided to the cold water valve, at least one characteristic of the hot water provided to the hot water valve, and at least one characteristic of the mixed water provided to the mixed water outlet. The method further comprises the steps of controlling the cold water valve and the hot water valve in a feed forward manner if at least one of the cold water and the hot water is unstable. The method further comprises the step of controlling the cold water valve and the hot water valve in a feedback manner only if both the cold water source and the hot water source are stable.
In yet another illustrative embodiment of the present invention, a proportioning valve system is provided for connection to a cold water source, a hot water source, and a mixed water outlet. The proportioning valve system is configured to deliver a mixed water of a desired temperature to the mixed water outlet. The proportioning valve system includes a cold water valve configured to be in fluid communication with a cold water source for receiving cold water. A cold water temperature sensor is configured to measure the temperature of the cold water supplied to the cold water valve from the cold water source and to provide a cold water temperature signal indicative thereof. A cold water pressure sensor is configured to measure the pressure of the cold water supplied to the cold water valve from the cold water source and provide a cold water pressure signal indicative thereof. A hot water valve is configured to be in fluid communication with the hot water source for receiving hot water. A hot water temperature sensor is configured to measure the temperature of the hot water supplied to the hot water valve from the hot water source and to provide a hot water temperature signal indicative thereof. A hot water pressure sensor is configured to measure the pressure of the hot water supplied to the hot water valve from the hot water source and provide a hot water pressure signal indicative thereof. A user input device is configured to receive the desired temperature from the user and to provide a set temperature signal indicative of the desired temperature. A controller is in communication with the cold water temperature sensor, the cold water pressure sensor, the hot water temperature sensor, the hot water pressure sensor, and the user input device. The controller is configured to regulate the mixed water temperature of the mixed water to substantially correspond to the desired water temperature by adjusting in a feed forward manner the cold water valve and the hot water valve in response to the cold water temperature signal, the cold water pressure signal, the hot water temperature signal, the hot water pressure signal, and the set temperature signal.
According to a further illustrative embodiment of the present invention, a proportioning valve system is provided for connection to a cold water source, a hot water source, and a mixed water outlet. The proportioning valve system is configured to deliver a mixed water of the desired temperature to the mixed water outlet. The proportioning valve system includes a cold water valve configured to be in fluid communication with the cold water source for receiving cold water. A cold water servo motor is coupled to the cold water valve and is configured to control the position of the cold water valve. A cold water temperature sensor is configured to measure the temperature of the cold water supplied to the cold water valve from the cold water source and to provide a cold water temperature signal indicative thereof. A hot water valve is configured to be in fluid communication with the hot water source. A hot water servo motor is coupled to the hot water valve and is configured to control the position of the hot water valve. A hot water temperature sensor is configured to measure the temperature of the hot water supplied to the hot water valve from the hot water source and to provide a hot water temperature signal indicative thereof. A user input device is configured to receive a desired temperature from the user and to provide a set temperature signal indicative of the desired temperature. A controller is in communication with the cold water temperature sensor, the hot water temperature sensor, and the user input device. The controller is configured to generate a cold water pulse width modulated control signal to control the cold water servo motor for positioning the cold water valve in response to the cold water temperature signal, the hot water temperature signal, and the set temperature signal. The controller is further configured to generate a hot water pulse width modulated control signal to control the hot water servo motor for positioning the hot water valve in response to the hot water temperature signal, the cold water temperature signal, and the set temperature signal.
According to yet another illustrative embodiment of the present invention, a water delivery system includes a valve configured to be coupled to a water source for receiving water, and defining a valve restriction. An actuator is operably coupled to the valve and is configured to control the position of the valve. An outlet is coupled to the valve, and a fluid delivery device is coupled to the outlet and defines an outlet restriction. An inlet pressure sensor is configured to measure pressure of the water provided to the valve. An outlet pressure sensor is configured to measure pressure of the water supplied to the outlet. A controller is configured to control the actuator for adjusting the valve in response to the inlet pressure and the outlet pressure, such that the valve restriction is substantially equal to the outlet restriction.
According to a further illustrative embodiment of the present invention, a water delivery system is provided for connection to a cold water source, a hot water source, and a mixed water outlet. The water delivery system is configured to provide a mixed water of a desired temperature to the mixed water outlet. The water delivery system includes a cold water valve adapted to be coupled to the cold water source and having a cold water outlet. A hot water valve is adapted to be coupled to the hot water source and includes a hot water outlet. A fluid mixer is configured to receive cold water from the cold water outlet, and to receive hot water from the hot water outlet. The fluid mixer includes a mixing element configured to separate the cold water into a plurality of spaced apart cold water streams and to separate the hot water into a plurality of spaced apart hot water streams. The fluid mixer is further configured to mix individual ones of the cold water streams and the hot water streams into a plurality of spaced apart mixed water streams. The fluid mixer is further configured to combine the plurality of mixed water streams into a combined mixed water provided to the water outlet. A controller is operably coupled to the cold water valve and the hot water valve, and is configured to adjust the cold water valve and the hot water valve to regulate a mixed water temperature of the mixed water to substantially correspond to the desired water temperature.
Additional features and advantages of the present invention will become apparent to those skilled in the art upon consideration of the following detailed description of the illustrative embodiment exemplifying the best mode of carrying out the invention as presently perceived.